Doubts and Questions from AC
what is phase difference?
what is resonance?
what is resonance?
and resonance frequency ?
From: jogesh
Date: Thu, Dec 20, 2012 at 4:16 PM
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Ask your doubts in Physics at AskPhysics.Com
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Date: Thu, Dec 20, 2012 at 4:16 PM
__________________________________________________________
Ask your doubts in Physics at AskPhysics.Com
Education News and Information www.Education2Home.com
Categories: Ask Physics, Current Electricity, Electromagnetism Tags:
Transformers
A hypothetical ideal transformer considered as a circuit element, consisting of N P turns in the primary winding, and N S in the secondary. Electrical power supplied to the primary circuit is delivered to the load in secondary circuit by means of mutual induction. The time-varying magnetic flux in the core generates an electromagnetic force over each of the windings. The voltage and current relationships are shown below. (Photo credit: Wikipedia)
Please explain what is transformer and tell what is the reason behind the working of transformer that it reduces potenial when current is high and increases potential when current is low?
Explain widely and deeply with concepts.
Answer:
Transformer is a device based on mutual inductance and is used to change the voltage of alternating (or varying) current. There are two types of transformers – stepup and stepdown.
A step-up transformer increases the voltage as the step-down transformer decreases the ac voltage.
When a transformer changes the alternating voltage, it is not adding any power, it only transforms the voltage.
As power is the product of voltage and current, as voltage increases, the current decreases. (and vice versa)
The following links will help you understand transformers in great detail.
- http://www.physlink.com/education/askexperts/ae427.cfm
- http://en.wikipedia.org/wiki/Transformer
- http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/transf.html
- http://www.nuffieldfoundation.org/practical-physics/explaining-how-transformer-works
Categories: Ask Physics, Current Electricity, Electromagnetism, Electronics, physics, Physics Videos Tags: Business, Electrical, Electronics and Electrical, High voltage, Inductance, Power Supplies, Substation and Transmission, transformer, Transformers and Inductors, Voltage
Current Electricity – Combination of Cells
12 cells,each of emf 1.5V and internal resistance, are arranged in ‘m’ rows each containing ‘n’ cells connected in series.calculate the values of ‘n’ and ‘m’ for which this combination would send maximum current through an external resistance of 1.5ohm.
Categories: Current Electricity Tags: ACS Nano, electric current, Health, Infrared, internal resistance, Polymer solar cell, Solar cell, University of California Los Angeles
Flow of electrons and direction of current
We say current flow opposite to electron flow but what is current?
Sid asked
Answer:
Electric current is defined as the rate of flow of charges, ie; the amount of charges flowing in 1 sec.
The direction of current was conventionally defined as the direction of flow of positive charges.
In a metallic conductor, the negatively charged particles (electrons) are moving and therefore the direction of current is taken as opposite to the direction of flow of electrons.
Hope the concept is clear.
Categories: Ask Physics, Current Electricity, Interesting Questions Tags: charge, current, electricity, electron
